Having lost her father at a young age, Kim Yoon Hee (Park Min Young) disguises herself as a boy to find odd jobs such as creating cheat sheets for the upper-class scholars to support her mother and sick brother. On the day of esteemed Sungkyunkwan University’s entrance exam, Yoon Hee mistakes scholar Lee Sun Joon as a client looking for her cheat sheets. His morals prompt him to turn her in to the officials but explaining her situation, Yoon Hee convinces him not to report her. Recognizing her intelligence, he instead offers her money to take the exam for herself. Still disguised as a boy, Yoon Hee takes the exam under her brother’s name and is successfully accepted into the school. Knowing that she will be expelled if the truth is revealed, Yoon Hee runs into a series of hijinks as she tries to keep her identity under wraps from the other students, including upper classman Gu Yong Ha (Song Joong Ki) and roommate Moon Jae Shin (Yoo Ah In.) Yoon Hee and Sun Joon, although not fond of each other at first, slowly start to forge a friendship.